That is a Very broad quesstion- one way to be sure you're running gnome apps, is to not install KDE or X; always check dependancies when yum installing to see if it needs to install X or Gnome, and that'll give you (imho)the best monitoring of what comes into your system to make sure you're using only gnome apps..
hope that helps
..the foolishness of fools is folly.. please suffer this fool until wisdom be acquired.. :D
Case: Thermaltake Xaser VI w/ bigwater wcs
Mobo; CPU; Mem: Asus m2n-sli Deluxe; Athlon64 X2 3.2Ghz (6400+); 4x Corsair XMS 2g (8g total)
Video: 2x XFX gForce 8600 GTS 256mb
Audio: Onboard (had emu 1820m, but card burnt- cust support took 4 months to reply, says to buy new. I'll never do emu again)
OS: Win64xp pro; Fedora 10 (x64); | other boxes: Ubuntu8.10 (x86); Fedora7 (x86)